Patent GB-656569-A (GB)
Title: Solid-fluid reaction processes
IPC: B01J19/26
Filed: 1948-03-10
Abstract: <PICT:0656569/IV (b)/1> <PICT:0656569/IV (b)/2> A process for conducting a reaction between a reactant in the form of particles of a frangible solid and a reactant in the form of a mobile fluid comprises mixing said reactants whilst maintaining them in movement in a closed path of at least partially curved form by fluid propulsion in which process the fluid propellant is introduced tangentially into the path from the outer side of a curved portion thereof where the reactants are subjected to the greatest compression so that the flow of the solid particles is disturbed in that region. The path may be of elliptical form having a vertical major axis, fresh materials being introduced at the lower part of said ellipse and reaction productions being withdrawn at a higher level.  The reactants may be caused to flow round a substantially cylindrical chamber having peripheral tangential inlets for propelling fluid and an outlet nearer its centre.  The process may be employed for the preparation of tetra-alkyl lead from lead-alkali alloy and an alkyl halide, ethyl magnesium chloride from magnesium and ethyl chloride, urea from calcium cyanamide and wet steam, oxalic acid from a carbohydrate and a mixed acid, sodium salicylate from sodium phenate and carbon dioxide, and vinyl chloride or acetate from calcium carbide and hydrochloric or acetic acid.  In the example, tetraethyl lead is prepared in the apparatus shown in Fig. 1.  Sodium lead alloy is introduced into hopper 1 and ethyl chloride from 14 in the form of a jet at 6 introduces the alloy through injector tube 4 into the reaction path 5, the alloy feed being controlled by 3.  Ethyl chloride is also injected at 7.  Reaction product is removed at 8 into the cyclone separator 9 and is sprayed with acetone through nozzles 10 and supply tank 24.  The ethyl chloride vapour undergoes scrubbing due to the effect of partial condenser 12 and passes upwards to final condenser 13 to 14.  The mixture of tetra-ethyl lead and acetone is collected in 11, filtered through 19 to stripping column 20 where the acetone is vaporized, condensed in 23 and collected in the acetone supply tank 24. Tetra-ethyl lead is removed from boiler 21 at 22.  Solid residue from 19 is removed by conveyer belt 25, is backwashed with acetone from supply line 30, heated with heater 27 to expel acetone which is taken off via 28 to condenser 23. Spent alloy is removed at 26.  Fig. 3 illustrates an alternative reaction chamber comprising a substantially cylindrical chamber 43 in communication with solid reactant feed 40 through Venturi feed line 41.  The Venturi feed line is also in communication with fluid line 42. The fluid jets 44 communicate with chamber 43 at the outer circumference.  The central portion of chamber 43 communicates with chamber 48 and line 50.  Chamber 48 is provided with a flange 47 which protrudes above the lower surface of chamber 43 while line 50 is of a smaller diameter than chamber 48, and the lower end of line 50 is set below flange 47.  Line 50 may be connected to a series of condensers while chamber 48 may be connected with chamber 11 of Fig. 1.  Specification 546,008, [Group III], is referred to.  The Specification as open to inspection under Sect. 91 refers to a process for reacting a frangible solid with a reactant in the form of a readily flowable fluid by mixing the solid and fluid under high speed turbulent agitation induced by fluid propulsion while the movement of the mixture is confined to at least a partially curved path, under reaction temperature and pressure conditions, and removing the more finely divided and substantially completed reacted portion of the reaction mixture.  This subject-matter does not appear in the Specification as accepted.ALSO:<PICT:0656569/III/1> <PICT:0656569/III/2> A process for conducting a reaction between a reactant in the form of particles of a frangible solid and a reactant in the form of a mobile fluid comprises mixing said reactants whilst maintaining them in movement in a closed path of at least partially curved form by fluid propulsion, in which process the fluid propellant is introduced tangentially into the path from the outer side of a curved portion thereof where the reactants are subjected to the greatest compression so that the flow of the solid particles is disturbed in that region.  The path may be of elliptical form having a vertical major axis, fresh materials being introduced at the lower part of said elipse and reaction products being withdrawn at a higher level.  The reactants may be caused to flow round a substantially cylindrical chamber having peripheral tangential inlets for propelling fluid and an outlet nearer its centre.  The process may be employed for the preparation of calcium cyanamide from calcium carbide and nitrogen, aluminium nitride and carbon monoxide from solid alumina, carbon and nitrogen, active carbon from solid coke and steam containing about 2 per cent by weight phosphoric acid, phosphoric acid and calcium sulphate from phosphate rock and sulphuric acid, titanium sulphate from concentrated ilmanite (or rutile) and concentrated sulphuric acid, and sulphur monochloride from sulphur and chlorine gas.  In Fig. 1, the fluid propulsion chamber 5 is fitted with tangentially disposed high velocity fluid jets 7, and the solid reactant is introduced into 5 from the hopper 1 through feed mechanism 3 and downwardly inclined injector tube 4 with the aid of injector 6. The exhaust 8 for the reaction products connects with cyclone separator 9 which is fitted with spray nozzles 10 and partial condenser 12.  The condenser 12 communicates with final condenser 13 which communicates with the fluid reactant feed tank 14.  The lower end of cyclone separator 9 communicates with closed chamber 11 equipped with strainer 19.  The strainer 19 communicates with the stripping column 20 which is attached at the lower end to boiler 21 with removal seal pipe 22.  A solvent supply tank 24 communicates with spray nozzles 10 and, through condenser 23, to the upper end of stripping column 20.  Ribbon-type conveyor 25 removes solid accumulated from strainer 19 and deposits the solid in vessel 26.  Conveyer 25 also communicates with solvent tank 24 through pipe 30 to wash down solid on the conveyer; solvent is removed as vapour with the aid of heating coil 27, and the vapour passes through pipe 28 and condenser 23 to the solvent tank 24. Fig. 3 illustrates an alternative reaction chamber comprising a substantially cylindrical chamber 43 in communication with solid reactant 40 through venturi feed line 41.  The venturi feed is also in communication with fluid line 42.  The fluid jets 44 communicate with chamber 43 at the outer circumference.  The central portion of chamber 43 communicates with chamber 48 and line 50.  Chamber 48 is provided with flange 47 which protrudes above the lower surface of chamber 43 while line 50 is of a smaller diameter than chamber 48, and the lower end of line 50 is set below flange 47.  Line 50 may be connected to a series of condensers, while chamber 48 may be connected with chamber 11 of Fig. 1.  Specification 546,088 is referred to.  The Specification as open to inspection under Sect. 91 refers to a process for reacting a frangible solid with a reactant in the form of a readily flowable fluid by mixing the solid and fluid under high speed turbulent agitation induced by fluid propulsion while the movement of the mixture is confined to at least a partially curved path, under reaction temperature and pressure conditions, and removing the more finely-divided and substantially completed reacted portion of the reaction mixture.  This subject-matter does not appear in the Specification as accepted.